Clavus – colloquially called hen’s eye – (crow’s eye, light thorn; ICD-10-GM L84: corns and horny (skin) calluses) refers to a local (circumscribed) cornification disorder of the skin (thickening of the horny layer of the skin), often on the foot, especially on toes.
Clavi are often caused by chronic pressure on skin near the bone or friction. They usually have a thorn of horny material in the center that extends deep into the skin and can be very painful. If the clavus occurs between the nail fold and the nail plate, it is called onychophosis.
Frequency peak: clavi occur more often in older people.
Clavi can be classified as follows:
- Localization
- Dorsal clavi (corns on the back of the toe).
- Plantar Clavi (corns of the soles of the feet).
- Interdigital Clavi (corns between the toes).
- Clavus subungualis (corns under the nail plate) Caveat (Warning)! A distal subungual clavus can also impose as a painful bleeding lesion (“injury”); due toDD (differential diagnosis / diseases with similar symptoms) to squamous cell carcinoma or melanoma is to note that in the clavus the distal end of the “neoplasm” is always at the extreme lateral (“lateral”) point of the affected toe.
- Onychophosis
- Consistency – Clavus durus (hard corn), usually located on the back of the toe or heel vs. Clavus mollis (soft corn), usually located between the toes.
- Morphology – Clavus vascularis (corn with capillaries), Clavus neurovascularis (corn with capillaries and nerve endings), Clavus neurofibrosus (scarred very deep clavus).
Course and prognosis: spontaneously (by itself) a clavus does not regress. The course or the prospects of recovery are better, the earlier the clavus is discovered and treated. The most important first therapeutic measure is the elimination of the triggering causes (e.g. tight shoes). Treatment is usually conservative (i.e., non-surgical). Keralytics (horn-dissolving agents, e.g. salicylic acid) are used in the form of plasters, solutions and ointments. If necessary, treatment should also be carried out by a podiatrist (medical foot care). Surgical removal with a sharp spoon is only necessary if conservative therapy has failed.
